Mold



Dec. 23, 1941. Y 1A J, MADER l 2,266,978

MOLD

Filed Feb. 29, 1940 2 Sheets-Sheet' l u Ir 'In w INVENTOR. JOHN J.MADE/e,

trarne/v Dec. 23, 1941.

MOLD

Filed Feb. 29, 19440 2 Sheets-Sheet 2 1NVNT0R.. JOHN J. MADE/l2 Y BWw/fa, fam/f .1.J. MADER 2,266,978

Patented Dec. 23, 1941 UNITED stars gir; orio-a MOLD John J. Mader,Parma, Ohio, assignor Vvtol'lhe Apex Electrical Manufacturing Company,

Cieveland, Ohio, a corporation of Ohio Application. February 29, 1940,Serial No. 321,525

4 `Glaims.

Itis a further object of my invention to pro-Y vide a method of makingan aluminum agitator in a permanent mold wherein the molten metal isconducted to the agitator casting cavity in a manner which will rapidlyll the casting cavity with an even flow of metal free of impurities, gaspockets and turbulence.

It is a further object. of my invention to provide a method of makingwashing machine agitators having vanos wherein the molten metal isconducted into the agitator casting cavity solely through the vaneportions thereof, so,- that the casting upon removal from the mold isfree of gates in the base portion thereof and the casting ischaracterized as being free of hot spots, air pockets and the like.

It is a further object of my invention to provide ay method of making awashing machine agitator having a plurality of vanes wherein the moltenmetal is led into the casting cavity by gates along the edges ofthevanes and such gates are` connected by a horizontally extendingbranch of a vertical pouring sprue.

It is a further object of my invention to provide a mold apparatus tocarry out the methods of the preceding objects wherein the agitator iscast with its axis vertical and the base of the moldv forms the base ofthe casting cavity, and

such mold base is free of gates along the baseo the agitator.

Further objects and advantages relating to economies in manufacture anduniformity in castings will appear from the following description andappended drawings; wherein Figure 1 is a sectional elevation of anagitator mold made according to my invention;

Figure 2 is a plan view of the agitator mold;

Figure 3 is a plan view with partsv in section showing a casting madeaccording tothe method and apparatus of my invention;

Figure 4 is an elevation of the agitator casting showing the gates andsprues attached;

Figure 5 is a plan view of an agitator casting showing a modified formof the invention;

Figure 6 illustrates a further modiiied form of,`

the invention; and l Figure 'Z is a sectional elevation taken. along.the lineA4 l-l of Figure. 6.

rEhe agitator type of washing machine has enjoyed wide use'and numerousmethods have been proposed for casting the agitators of `aluminum inpermanent` molds. Among the successful methods of casting such agitatorsis that method disclosed in the patent to Fahlman 1,770,368, wherein theagitator is cast in a vertical position with the-base of the agitatorresting on the base of the mold, and wherein the molten metal isvconducted into the casting cavity through. a ring gate surroundingthebase of the casting cavity. This method, although generally productiveof good castings, results in'a` castingrequiring a large volume of metalin the gate, which metal must be removed from the base of the agitatorand the base machined throughout. its gate area. Since the gate andpouring sprues are scrap metal, the use of the Fahlman method results inconsiderable waste due to the arrangement and proportions required inthe gate.

According to my invention, I propose to eliminate any gate around theperiphery of the base of the agitator casting and thus reduce the volumeof scrap metal and the attendant machining costs on` the base of theagitator following the removal of the gate.

I, have obtained the 'objects above enumerated by leading Vthe moltenmetal into the casting cavity in the vaned portions. thereof throughrelatively-small, vertically-disposed gates, so shaped and proportionedthat the molten metal iiows quietly and smoothly into theA castingcavity. The gating arrangement. along the vanes of the agitator is soproportioned and arranged with respect to the pouring sprue and thecasting cavity that any impurities which may Vbe carried in the moltenmetal are trapped in the gate and thevmolten metal is so conditionedprior to its entrance into the casting cavity that the resulting castingis free oi -hot spots, bubbles or otherdeects. Y v v Myinvention-contemplates the use of a permanent mold such as that .shownin Figure 1 of the drawings, wherein the base` 6 of the ymold issupported by a plurality of legs 'l and a plurality of movable moldsections 8, 8 and I0 are pivotally carried by the base' 6'. A,reciprocable core It projects upwardly through the center of the moldbase 'E and the movement of the core H is controlled by'a shaft l2having a rack I3 thereon at its lower end.` A horizontal shaftlllmounted in 'bosses I5 and i6 in the supporting structure` of the mold'isprovivsied"wi-thl gear teethv |17 adapted to mesh with' the teethof therack lf3/on the verticallyreciprocab1e core shaft I2, Movement of thecore member II is thus effected by a inanual movement of the handle I8producing rotation of the horizontal shaft I4. The movable core sections8, 9 and I0 are shaped along their abutting faces to follow the contourof the spiral vanes 2|, 22 and 23 of the agitator casting indicated inits entirety as at 29.

The mold sections may be swung outwardly away from the base 6 of themold upon the pivot pins 24 which are carried in depending brackets 25,integral with the mold base. The base of the mold 6 is conical in formso as to provide a conical base for the agitator and since the agitatorincludes 3 vanes, each of the three mold parts 8, 9 and I0 are cut awayat their abutting surfaces to provide the casting cavities for thevanes.

In the preferred form of my invention, two pouring sprues 21 and 28 areprovided, a complementary half of the pouring sprue 21 being formed ineach of the abutting surfaces of the mold sections 9 andV I8 and thecomplementary portions of the sprue 28 are formed in the abuttingsurfaces of the mold sections 8 and I0. The pouring sprues terminate attheir lower ends at the top surface of the base 6 of the mold andextending laterally from the pouring sprue at a point spaced from thebase of the mold is a gate comprising three adjoining sections 29, 39and 3|. The section 29 is narrow in cross section and leads the moltenmetal into the section 30 which has a gre'ater vertical extent and amuch lar-ger cross section than the section 29. The section 3| isrelatively thin and one of the advantages of this construction is thatit facilitates the removal of the gate and pouring sprue from the vaneof the agitator casting.

When the mold has been conditioned by heating to appropriate castingtemperature, the mold sections are secured to each other by mold clamps33 and the molten metal introduced to the casting through the pouringsprues 21 and 28. The rst metal out of the ladle into the sprue fillsthe lower end of the pouring sprue up to the restricted gate section 29.The restricted flow of the metal through section 29 eliminatesturbulence and splashing resulting from the vertical drop of the metaldown the pouring sprue. The

level of the molten metal rises in the sprue and in the lower end of thegate section 30 until it the molten metal'owing through the lowerportion yof section 3| into the casting cavity is free of bubbles andimpurities. Such metal, being heated by the molten'mass in the gate,fiows evenly downwardly from section 3| to ll the( 5.`

base portion of the casting cavity. As the casting cavity continues tofill, the metal rises evenly therein and the gate 29-30-3I carriessufficient molten metal at the proper temperature to compensate for thecrystallization shrinkage characteristic of aluminum and other lightmetal alloys. The air in the casting cavity' is gradually forced out ofthe cavity through the parting lines of the mold sections as the metalrises in the GEW-ity. i.

After the casting has been poured and set, the' mold clamps 33 are freedof the mold sections and each mold section swung outwardly by means ofthe handles 36 and 31 about the pivot axis 24. A rocking of the handleI8 effects a withdrawal of the core II to free the same of the casting.The casting, including the sprues and gates, is removed from the moldand the sprue and gate removed from the vane in the weakened orrestricted section 3 I.

Although I have found that a three-vane agitator of the type illustratedmay be satisfactorily Y poured with two pouring sprues and two gate Y,vcontinuous ring 54. 40

arrangements, I am aware that the pouring of other types of agitatorsmay require additional gating arrangements. To facilitate the casting ofagitators requiring additional gating metal, I have shown a modificationin Figure 5 wherein a three-vane casting indicated in its entirety at 48is provided with a gate of the type shown in the preferred form alongeach of the agitator vanes. Two of the gates, namely 4I and 42, areprovided with pouring sprues 43 and 44. The third gate 45 lacks avertical pouring sprue but is connected to the pouring sprue 44 by `abranch 46 leading therefrom. The branch or cond-uit 46 connecting thegat-es 42 and 45 to each other is formed by an arcuate groove in themold base as indicated in Figure 7. By this arrangement molten metalfrom the pouring sprue 44 flows laterally through the groove 45 aroundthe base of the agitator to the gate 45. The gate 45 being proportionedto have the two restricted sections filled in the manner heretoforedescribed in connection with the preferred embodiment.

A further modification of my invention is illustrated in Figure 6,wherein all three gates 5l, 52 and 53 are connected to each other by aTwo pouring sprues indicated at and 56 are employed and metal from thepouring sprues 55 and 56 may flow laterally to the gate 52. The gate 52being proportioned and arranged like the gate of the preferred em- Abodiment, conditions and feeds the molten metal into the casting cavityin a manner like that described in connection with the preferredembodiment.

In all three forms of my invention, it will be observed that the base ofthe agitator casting is free of gates and requires no machiningoperations such as are required where the casting cavity is filled byintroducing the molten metal around the base of the agitator.

It will also be observed that in the preferred I' embodiment of myinvention, the scrap metal to be removed from the casting comprises onlythe two pouring sprues 21--28 and their associated gates. The reduction'in the amount of metal required for each casting and the reduction inthe machining operations results in high speed production of soundcastings.

Although I have shown and described three forms of my invention inconsiderable detail, it

.will be appreciated that modifications may be made therein withoutdeparting from the scope of my invention as defined in the followingclaims.

Having thus described my invention, what I claim is:

1. A permanent mold for casting aluminum agitators having a base portionand upstanding impeller vanes, said mold having a casting cavity withthe agitator base portion thereof horizon- `tally disposed, a pouringsprue extending downvwardly from the top ofthe mold to the plane of saidbase portion and spaced laterally from said base portion, said baseclosing the lower end of said sprue, a single vertically disposed gateconnecting said sprue and that portion of the casting cavity forming thevane, said gate comprising three sections, one section being arestricted section adjacent the sprue, a second section being arestricted section adjacent the vane and the third section being anenlarged section between the two restricted sections, said third sectionhaving a vertical extent greater than the vertical extent of the othertwo sections.

2. A permanent mold for casting aluminum washing machine agitatorshaving a base and upstanding vanes comprising a mold base and aplurality of separable mold members recessed to define a casting cavitywith the base portion of the agitator horizontally disposed, said moldmembers being further recessed to define a vertically disposed spruecavity, said sprue cavity closed at its lower end by said base spacedlaterally from the casting cavity and a vertically disposed gate betweensaid sprue and a vane portion of said casting cavity, the juncturebetween said vane and gate being above the lower end of the sprue andabove the base portion of that part of the casting cavity forming thebase of the agitator, whereby impurities in the metal are trapped in thesprue and gate and the molten metal is conducted into the casting cavitywithout turbulence.

3. A permanent mold for casting aluminum agitators having a base and aplurality of upstanding impeller vanes, said mold having a castingcavity with the agitator base portion thereof horizontally disposed, aplurality of movable mold sections having abutting faces recessed toform a casting cavity for an impeller vane, said abutting faces beingfurther recessed to provide a gate cavity, certain of the abutting facesof the mold sections being further recessed to provide pouring spruesand other of the abutting faces being free of pouring sprue recesses, afixed mold section beneath said movable sections providing a support forthe movable sections and forming the base of the agitator castingcavity, said xed mold section provided with a groove extending about thebase of the agitator casting cavity to provide a passageway to conductmolten metal from the pouring sprues laterally to a gate cavity formedin said other abutting mold faces which are free of pouring sprues.

4. A permanent mold for aluminum agitators having a base portion and aplurality of upstanding impeller vanes comprising a fixed mold base anda plurality of movable mold sections mounted thereon, the number ofmovable mold sections corresponding to the number of impeller vanes onthe agitator casting, all of the yabutting faces of the movable moldsections being recessed to provide vane portions of the casting cavityand gates along the vertical edges of said vanes, certain of theabutting faces of certain of the mold sections being further recessed toprovide pouring sprues connected to said gates, and other of theabutting mold faces being free of pouring sprue recesses, an annulargroove formed in the xed mold section connecting said pouring sprues andgates, whereby molten metal is conducted laterally from the bottom ofthe pouring sprues to said other abutting mold faces which are free ofpouring sprue recesses.

JOHN J. MADER.

